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Structure of (C 5 H 5) 2 TiSe 5. Polyselenides are prone to decomposition on exposure to air, in which case they are oxidized back to elemental selenium. Se 2− n + 2 H + + 1 ⁄ 2 O 2 → n Se + H 2 O. As ligands in coordination complexs, polyselenides are generally bidentate. Complexes of penta-, tetra-, and triselenide ligands are known.
Selenium IDE is a complete integrated development environment (IDE) for Selenium tests. It is implemented as a Firefox Add-On and as a Chrome Extension.It allows for recording, editing and debugging of functional tests.
Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. [1] Selenium-containing proteins are produced from inorganic selenium via the intermediacy of selenophosphate (PSeO 3 3 ...
Selenium is a vital nutrient in animals, [7] including humans. About 25 different selenocysteine-containing selenoproteins have so far been observed in human cells and tissues. [ 8 ] Since lack of selenium deprives the cell of its ability to synthesize selenoproteins, many health effects of low selenium intake are believed to be caused by the ...
For example, selenomethionine and selenocysteine are selenium-containing amino acids present in the human body. Selenomethionine participates in the synthesis of selenoproteins . [ 2 ] The reduction potential and pKa (5.47) of selenocysteine are lower than those of cysteine , making some proteins have antioxidant activity. [ 3 ]
Selenocysteine has the same structure as cysteine, but with an atom of selenium taking the place of the usual sulfur. It has a selenol group. Like other natural proteinogenic amino acids, cysteine and selenocysteine have L chirality in the older D / L notation based on homology to D - and L - glyceraldehyde .
Selones (R 2 C=Se) are the selenium analogues of ketones. They are rare due to their tendency to oligomerize. [11] Diselenobenzoquinone is stable as a metal complex. [12] Selenourea is an example of a stable compound containing a (formal) C=Se bond. Thioselenides (R−Se−S−R), compounds with selenium(II)–sulfur(II) bonds, analogous to ...
Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.